Centrifugal humidifier



April. 7, 19M. F. B, coMlNS I CENTRIFUGAL HUMIDIFIER Filed Aug. 7, 1925 2 Sheets-Sheet Patented Apr. 7, l1931 UNITED. STATES `PARENT OFFICE FRANK B. COMINS, 0F NEWTON, MASSACHUSETTS, ASSIGNO'R TO AMERICAN MDISTEN- ING- COMPANY, OIF PROVIDENCE, RHODE ISLAND, A CORPORATION 0E MAINE CENTRIFUGAL HUMIDIFIER Application mea August 7, 192s. yserial no. 656,239..

This invention relates to improvements in centrifugal humidiiers. Although apparatus is herein illustrated as it may be used for humidifying air, by breaking water into very small particles which are entrained in the air as fog and which promote the passing 4of the water i'nto vapor that is invisible 1n lthe air, it will be understood that it may bev applied with various liquids and gases for the general purpose of breaking up the liquid into fog and disseminating its vapor through that gas which is passing through the apparatus.

In apparatus of the general type to which the invention pertains, the liquid, in the present case assumed to be water, is put upon the surface of a`disk-like member whose rotation spreads it into a thin film and throws it from the edge of the disk by centrifugal force against a series of blades with such speed and at such an angle of impact that the water is atomized by the mechanical shock. The particles thus made are -entrained in and are absorbed by the air in a 'current which is provided by the apparatus; and

moisture is thus disseminated in the atmos# phere.

It is an object of the inventiont'o make it possible to build ap aratus having higher capacity for a unit o -given size; higher ei'li- Aciency of transformation of liquid into the fog and into the gaseous form; more distant 4 distribution from each single unit of the apparatus; and withal to maintain simple construction for the apparatus itself, and eventol simplify construction, as compared with some previous apparatus, so as to avoid the discharge of particles too large to be entrained, while the apparatus nevertheless is operating at high speed and high output and without various protection devices that have heretofore been thought necessary. A

It is also the object of the'invention to provide other features of improvement which will appear from consideration of the apparatusl herein described. i

For the accomplishment 'of these objects the invention provides for the customary constant speedl electric moltor and fan to make anA airv current; and the customary ro- -rents or eddy currents passin tating disk and stationary 'surrounding row of thin sheet metal atomizing blades with edges presented radially-toward the edge of the disk, all of which features may be of any ordinary or suitable type. But` as regards; the means for the successful conversion of the dying film into fog and its distypes, heretofore regarded as standard, have been greatly exceeded by the results attained by the present invention, "wherein, without any shielding of thev incipient fog, there is provision for action and interaction of gaseous forces within the blast, and for instant distribution of the small water masses through the whole air current, and for separation therefrom of such globules as are too yThe eiciency and capacity attained by those large to be carried away by the current and to be sustained in the atmosphere. The flying and pulverized fragments of water, rebounding from their impact on the blades, are thrown and blown into drier portions of the main current which have avoided actual contact with the blades.

Just before reaching the blades, the whole broad air current from the fan is deiected sharply from a direction of general perpendicularity to the plane of the zone occupiedv by these blades to a direction of general parallelism with that plane. In doing so it passes around a sharp corner in the walls of its guiding passage. A portion of the air cul-,

rent.- is directed Aagainst and between the atomizing blades and constitutes cross-curinto and across the main body ofy air w ich passes clear of the plates. The eddy currents thus pick up and carry into the main body of air the ying fragments of water in the atomizing region. Water fragments which could not be permanently held by the eddy currentsv being blown out thereby, while draining ree ly back to the well whence they came. As a result the entire large current or" air becomes laden within the apparatus; and inasmuch as f it nowhere encounters a serious obstruction to its flow, and as it is projected as from a nozzle, it iows with considerable momentum, greater than in apparatus which has hereto fore been proposed, and so can carry the current farther through the surrounding atmosphere and thus can make distribution of moisture greater both in rate of water consumed and in eilective distance of projection.

Other features will be found in the descrip tion which follows, it being understood that the invention is not limited to the particular details which are chosen for illustration.

The invention is illustrated as it may be applied to apparatus operating on the vertical aXis, because When thus arranged, the shaft on which the rotating parts are mounted can conveniently be continued down into a basin containing the supply of liquid to operate a pump for supplying water to the rotating disk.

It is intended that the patent shall cover, by suitable expression in the appended claims whatever features of patentable novelty exist in the invention disclosed.

In the accompanying drawings:

Figure 1 is an elevation, partly in section showing a humidifier embodyingY the present invention;

Figure 2 is a plan of a portion of the atomizing blades;

Figure 3 is an elevation on a larger scale, in cross-section, showing the details of the blade mountings;

Figure 4 is an elevation of a portion of the apparatus showing a rotor arranged with its discharge edge above the horizontal medial plane through the blades;

Figure 5 is a side elevation of the complete humidifier;

Figure 6 is an elevation in section on line 6 6 of Figure 1; showing the Vwater lifting means;

Figure 7 is a section on line 7-1 of Figure6;and

Figure 8 is a plan of the valve, seen in blades 14 of a fan, (which may be omitted if desired) the rotor 15 whose function it is to throw the liquid centrifugally, and the screw 16 whose function it is to lift the liquid from beneath. This screw is closely surrounded by a tube 17 supported rictionally thereon and adjustable toward or from the rotor to vary the distance between its flared upper endA 17a and the underside of the rotor.

The space below the lowest thread of the screw is filled to a plane flush with the end of the screw thread and extended halt way around the axis of the screw as at 16". A plate valve 16h regulates the opening through which the water passes from the well into the thread valley 16" which remains open, leading to the rotor. As illustrated in Figures G and Z the plate valve may be clamped at diderent angular positions by the set screw 16d to vary the size of the opening and thereby to govern the maximum amount of water lifted by the screw. At a suitable distance under the rotor is the bottom 18 of the pan which supports the stationary atomizing elements 20, consisting of a helical strip ot metal providing a series of thin plates or blades, set vertically, edgewise toward and around the periphery of the rotor disk l5, and rather close thereto, with the plane of the disk intercepting them so that liquid thrown centrifugally from the edge of the disk strikes them violently. The pan has a rim portion 19 extending outward a little further, with the function of catching any drops or globules which may be too heavy to be entrained in the current of air, and has the bottom portion 18 sloping inward to lead any such drops from the rim or such heavy globules as are entrapped by the blades themselves back to the well 21 in which the screw and tube, 16, 17, are set. This well is illustrated as a tubular downwardextension of the middle of the pan 18, the junction point being also a point ot support where the pan rests on a base 18'* on which the apparatus might stand. The well is extended downward by a pipe fitting suitably connected to the supply pipe 22, through which the water that is to be atomilzedvmay be supplied.

The atomizing means 20 herein illustrated consists of a continuous helical strip of thin sheet metal attached edgewise to a base rod 23 along which a thin fin 24 is provided having notches into which the convolutions of the helical strip are fitted to insure and maintain proper spacing between them. The rod is supported a little above the pan 18 by leg plates 25, so that the excess water which trickles back along the pan ma pass freely under the atomizing means. T e inner portions of the helical strip constitute vertical blades presented toward the edge of the rotor against which the film strikes to be broken up by shock, the central hole through each convolution minimizes the surface 'on which fog may condense and the outer portions help perfect the absorption of globules by the passlng air, by acting as rebound plates for break- -ing up the globules still finer, or, serving as entrapping means, by gathering and leading the heavier particles downward to the pan.-v

The movement of the air past the blades may be effected by the rotor alone or by the particles and because an induced blast of air through the casing materially increases the capacity ofthe apparatus.-

For directing the'air blast there is a short vertical sheet metal casing 26 around the fan with a bottom flange 27, departing from it at nearly a right angle. This is set some little distance above the aring edges 19 ofthe jpan, lso that the two together form a pair of circular lips between which the current of air from the fan issues in all directions. .approximately perpendicular to the vertical axis. The rotor constitutes an abrupt end to the vertical art of the air passage, and is the bottom ace or wall of thel first part of the horizontal part of that passage. The blades 20.are of such size that they rise above the edge of the rotor and project into the air passage. Being located beyond the peripheral limits of the rotor they are exposed to the full force of the blast of air, as is also the film of water at the po-int where it encounters the blades, after having left' the underside of the' disk and while flying centrifugally outward therefrom. Therefore there is a large supply of air to pick up and carry on at high speed such globules as are formed by the mechanical shock. But only a minor part of the air blast actually passes between the blades, in apparatus designed in the proportions herein illustrated. The remainder is closely at hand extending across thepassage between the lips 19 and 27 Such water particles as result from the shock quickly pass into the adjacent more arid parts of this air :.urrent, a result which occurs naturally due hto the momentum of the liquid when it strikes the blades, and vwhich ils greatly expeditedby eddy currents in the air which carry moisture and globules directly out into the main stream. Within the space of the few inches from the blades to `the discharge lips, substantially the whole breadth of the current' entrains moisture somewhat in gaseous but-more especially in minute globular form.

As regards the eddy currents, the air blast from the fan, in moving almost vertically downward to the upper surface of the rotor, past the nearly right angled flare 27, tends to lcreate a raried zone close up under this flare 27. This, together with the sha-rp. deflection of the air blast caused by its impact on the horizontally disposed surface of the rotor, to which possibly the whirling effect produced by the rotation of the rotor may also be added as a contributing cause, results in an eddying of the air under the flare 27. 'lhis eddying may be varied by raising or lowering the level of the flaring lip 27 with respect to the li 19; also by modifying the abruptness of tiie angle of liaring. The transfer of the fog particles across the passageway takes place so quickly and so eifectively that the under side of the flare 27 becomes covered with a thin film of water. In apparatus which I have used the presence of the eddy current is manifest by the immediate appearance of the deposit of water on the ceiling of the passage wherein the powerful airA current is blowing past the blades. By making the apparatus with this ceiling higher, thus providing a deeper passage, or by making the passage with a less abrupt corner around whichv the currentmust turn, the eddying effect is diminished and the capacity of the apparatus, as measured by the quantity of water per unit of time lwhich it can atomize and distribute diminishes at the same time. The ceiling over the blades is preferably inclined slightly downwardly and outwardly, so that thelilm which clings thereto runs along its under face until 1t reaches the depending terminal aprons 28. These aprons are provigded along their lower edges with a shallow gutter 29, comprising an inturned edge which collects the water, keeps it from dripping, and leads it to depending points 29 behind the supporting posts 30 in whose shelter drops of water may form and fall freely into the pan 18, in quiet air, without this they Vwould be blown out into the atmosphere by the passing air current. A

Experiment has shown that with apparatus 'thus described the blast of air can be so large as to carry away moisture at a much higher rate uthan has been-possible with any. style of humidifier heretofore known to me, lwithnitude as will go beyond the lips and fall upon the ioor. I believe this to be' due to the fact `that the current of air blows directly upon the blades; that at the instant of its contact therewith the' adjacent partv of the current provides free relief for the enhanced vapor tension in that part of the air current which goes through the blades, thus minimizing condensation; and that the ampleness of space together with the eddy currents gen- 11:.

erated therein, makes it possible that the quantity of passing air, with potential moisture-carrying value, is so lar that it can pick u a great quantitywithin the apparatus.

xcess of moisture initially spattered into that part of the air which iiows between the blades does not have to be carried by that particular air so far as to have danger of falling to the ground before it finds access to other air that will carry it.

lt is desirable that the atomizing blades be kept sharply clean and clear of lint and the like. lnasmuch as the locations where humidiiers are most used are in rooms in mills where the air is filled with floating lint, it is desirable to provide a sheltering cover 3l to keep the lint from settlinginto the apparatus. Such lint as is carried in by the current of air is in the main driven past the blades without touching them, because they are so thin, and project into only a small part of the width of the air current. in consequence the bla-des need to be cleaned only infrequently.

The rotor is preferably a shell made of sheet metal of the general type shown, in which the under surface is the water carrier and the upper surface is a guide for the air current. The peculiar rising and spreading shape of the under surface causes the flow of .Water thereon to be upward and outward as it clings thereto, and is subjected to centrifugal action, from the place where it is delivered to the disk by the worm and cone. Some other form of delivery of water to the under or upper face of the rotor might be substituted if preferred.

In ordinary operation themotor and fan may run continuously; and the apparatus will function as a humidifier or cease according as the control valve 32 for the Water supply is open or closed. Preferably the water is supplied to the well by any suitable means which tends to maintain it at a constant level, but if more convenient the supply maybe in continuous stream 0r intermittent.

I claim as my invention: e,

1. The combination with a centrifugal liquid-bearing rotor, and atomizing elements surrounding it, of means to produce and guide an air current past the elements, comprising means set in the path of the air and arranged to deiect the current whereby the current is banked against the elements on the upper side thereof, the Whole being arranged portion and projecting part way into it,.`

whereby a part of the blast flows through the elements, and a part flows past free from contact with the said elements and their drip.

3. The combination with a centrifugal rotor with liquid-bearing surface on one side, and atomizing blades surrounding the rotor, of a power fan; and a support and drainage wall for and under the said blades on the liquid bearing side of the rotor, said fan being on the other side; the said blades being arranged projecting to said other side and leaving a passage for the air current beyond the extreme to which they thus project.

a. rlhe combination with a centrifugal liquid-bearing rotor, atomizing blades Vsurrounding it.v and a power fan, the whole being arranged around a vertical axis with the fan above the rotor, of an air confining wall guiding the blast from the fan above thc rotor, and a wall for drainage of water under p the rotor; the said blades being supported from the last said wall, and projecting into only a portion of the said guided course of the blast; and the said guide being positioned for making the said course mainly to avoid said blades in passing them.

5. llhe combination of a centrifugal liquidbearing rotor, arranged on a vertical axis, a pan under it; a continuous rod circling around the rotor on the pan; atomizing blades secured on the rod, and means elevating the rod above the pan and permitting drainage under said rod.

6. The combination with a centrifugal liquid-bearing rotor, and atomizing blades surrounding it, of means providing a coniined wide current of air having its passage and outlet substantially unobstructedlin radial direction past and above the blades;

said blades being at the edge of said current.

and the said unobstructed passage permitting free passage of moisture particles rising across the air current from the blades.

7. The combination with a centrifugal liquid-bearing rotor, atomizing blades surrounding it, an approximately parallel airguide platev at alittle distance therefrom discharging air horizontally without deflection from the direction of the rotors surface, and a power fan driving air between the rotor and the guide; of stationary bars extending across the air space to the guide; the said guide being inclined slightly in the direction of iow, for liquid coming to it from the atomizing section to pass by gravity to its edge; and its said edge having sectionsinclined transversely with respect to the flow of air and leading to drip points behind said bars, whereby water which has coalesced on the guide drips in shelter from the blast.

8. The combination with a centrifugal liquid-bearing rotor, atomizing Vblades surrounding it, and a power fan driving air radially across the rotor and blades, the Whole being set around a vertical axis; of an air guiding plate above the rotor, between which and the rotor the blast passes radially horizontally into the atmosphere; and formations in said air guiding plate whereby Water coalesced thereon runs by gravity to concentration points for flow to the underside of the blast.

9. The combination, with a centrifugal liquid-bearing rotor arranged on a vertical axis, a pan below, holding a supply of liquid; means above for guiding a current of air, and a power fan for making said leurrent, the Whole having atomizing blades and being arranged to guide the air radiaily across the blades; structurai uprights at intervals across said current oi air; and drip points on said guiding areas, arranged4 beyond said uprights, for liquid coalesced on the said guid ing means. y

l0. The combination with giiide walls, a centrifugal liquid-bearing rotor, and atomizing blades surrounding it, oi a power fan arranged to drive a current oi air radially across the rotor and blades; the Whole being arranged for guiding the air through a course which has considerable width :free oi. the blades in passing them, and is outside of the zone of drip from said blades; there being also a free space around the rotor and beyond the blades; and the said guidewalis and the rotor, being positioned for discharging into said free space the said air which is dis charged radially and that air which is moved centrifuga-Hy by the rotor.

l1. rllhe combination with a rentriugal liquid-bearing rotor and atomizing elements surrounding it, oi means to producen current of air, andmeans to guide said air Acurrent past the said elements comprising a Wall direoting the current initially in the direction oi the axis of and toward the rotor and then turning so as to pass the air bythe elements in a, once-ebanged direction which is substantially perpendicular to the initial direction of the current; the said elements being arranged adjaoent to the rotor and spaced away from said Wall, wherebyr a part of the air flows through the elements and' a part Hows past them free from contact with them.

12. The combination with a .centrifugal liquid-bearing rotor adapted to discharge the liquid therefrom horizontally and atomizing elements surrounding the rotor in position to be struck by said liquid; of a fan producing a current ofair; and means comprising a wall initially confining said current and guiding it toward said rotor so that the latter deects part of the air into parallelism with the horizontal discharge of the liquid; the said wall being spaced apart from said elements and turned so thata part of the air current can pass said element without coming in contact with them.

i3. The combination with a liquid-bearing Vrotor, and atomizing impact e ements sur- 

